atomicmak
Posts: 173
Location: ahmedabad, India
Registered: 7 Dec 2006
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sigma 8mm problem or what ?
Posted: 8 Dec 2006 at 9:28 GMT
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can someone suggest best method to focus my images?
it seems very unfocus.
i use d200, sigma 8mm F4 at infinity.
looks like something is wrong at my lense or configuration.
i found here many people who have very perfect sharp pano's where here with me its very unfocus so if i use ultrasharpen then also it becomes not much clear with depth.
please guide.
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Hans Nyberg
Posts: 866
Location: Denmark
Registered: 28 Aug 2005
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Re: sigma 8mm problem or what ?
Posted: 8 Dec 2006 at 10:50 GMT
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Your image looks very sharp to me.
But you have some CA which you need to remove.
Best done in Photoshop Raw conversion.
Always use RAW of course.
Hans Nyberg
www.panoramas.dk
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mshakeshaft
Posts: 97
Location:
Registered: 3 Mar 2006
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Re: sigma 8mm problem or what ?
Posted: 8 Dec 2006 at 10:53 GMT
updated: 8 Dec 2006 at 10:55 GMT
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Looks fine to me. But you might want to try:
The image was shot at f5 - I always use f8 with this lens as it gives optimum results.
As the lens suffers from chromatic aberration, I prefer to shoot RAW (or NEF in your case) where it can be corrected in either the Nikon NEF converter or CS2 Raw converter.
The key to the Sigma 8mm is sharpening, I use a mixture of Ultrasharpen Pro 7 and Convolution Sharpening (based on suggestions from John Houghton).
When you say you focus on infinity what do you mean - for this lens the hyperfocal distance is 1.6mts Try focusing on that.
With proper sharpening the image looks fine to me.
Martin
(Hans posted as I was typing this, it looks like we had similar thoughts)!
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atomicmak
Posts: 173
Location: ahmedabad, India
Registered: 7 Dec 2006
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Re: sigma 8mm problem or what ?
Posted: 8 Dec 2006 at 10:53 GMT
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thanks hans.
i always shoot raw and use nikon capture editor OR photoshop both.
i produce pano with ptgui and then use sharpen in spherical and produce final output in qtvr/java whatever client needs.
but still i dont find much sharpness and focus with my 8mm f4.
i have seen so many pano over here on forum which are too much sharp and made from d200 and sigma 8mm/ 10.5mm nikkor.
just cross checking if i am doing anything wrong with my images sigma 8mm.
my panos are on my site www.vox360.in if someone can give me feedback on quality.
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